Total contact cast

ABSTRACT

A method of constructing a total contact cast, that includes the steps of wrapping a lower leg with foam from above the malleoli to mid-calf, covering the foot and lower leg with stockinette; covering the foot and ankle with cast padding, and applying cast tape to the leg over the previously-applied foam and allowing the cast tape to harden. A foam pad and lateral and medial malleolar pads are applied to the leg section of the cast and a foot and ankle positioning device is applied to the leg, and cast tape is applied over the lower leg and foot and allowing the cast tape to harden. A walking support is applied to the foot. A foot and ankle positioner for a total contact cast is also disclosed.

TECHNICAL FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to a total contact cast, particularly ofthe type used to treat wounds often encountered by diabetic patients. Atotal contact cast is designed to redistribute plantar pressures andreduce shock and shear forces that contribute to tissue breakdown andthat interfere with the normal healing process of open plantar ulcers onthe diabetic foot. The application of appropriate structures to reducepressure on pedal wounds and alter a patient's gait to prevent injury orreinjury of the tissues requires the use of several types of devices andfootwear during the course of healing. The healing and post-healingstages are both important in the overall treatment sequence sincetreatment must include not only actual healing, but treatment afterhealing when newly healed tissues are thin, fragile and subject to beingreinjured. Ideally, a proper treatment procedure should not only healthe wound but also protect delicate, recently healed tissues fromfurther breakdown during the wound maturation process.

Some practitioners are reluctant to use a total contact cast. Reasonsmay include inadequate training, a lack of confidence to administer thetreatment, a wound caused or made worse when using the treatment, orpoor compliance demonstrated by diabetic neuropathic patients. Thepractitioner must trust a patient to follow the treatment protocol. Apatient who has a demonstrated history of poor judgment in managing hisor her care, with the restrictions imposed by prior art total contactcasts has reduced the use of total contact casts in the past.

In order for diabetic sores and wounds to heal, substantially all of thepatient's weight must be removed from the sore or wound, many of whichoccur on the balls of the feet.

Most practitioners treating diabetic wounds use a number of alternativeoff-loading devices due to a perceived complexity of applying totalcontact casts, concern for complications reported in the literature, thecost of materials for the device, reimbursement concerns, and a fearthat application of the total contact cast will take too much time.Alternative devices used by practitioners include a removable castwalker, non-removable cast walker, instant total contact cast, molded ordouble upright ankle foot orthosis with or without a patellartendon-bearing addition, Charcot restraint orthopedic walkers, modifiedCarville healing sandal, football dressing, commercial off-loading shoessuch as the half or wedge shoes or wound care shoe systems, standardpost-operative shoe, and depth or custom-molded footwear.

Most practitioners choose between these devices based on theirindividual experience with a particular modality, clinical availability,patient preference, or insurance reimbursement. The most commonlyemployed device is the surgical shoe with or without internal shoemodifications despite relatively poor evidence for healing when comparedto the total contact cast or the instant total contact cast.

The diabetic patient is a complicated and often frustrating entity totreat. Patience, persistence, and a commitment to the patient arerequired to achieve a satisfactory result. There is therefore a need foran application method and components that allow practitioners to applyan effective total contact cast without the worry of cast misapplicationcommon to total contact kits presently on the market. An idealresolution produces a suspended foot within a rigid external totalcontact limb-load cast capable of supporting even the heaviest patient.There is also a need for a total contact cast that can be applied by asingle practitioner without assistance.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide aneffective total contact cast that will efficiently utilize the benefitsdesired when using a total contact cast.

It is a further object of the invention to provide an effective totalcontact cast that improves treatment outcomes.

It is a further object of the invention to provide an effective totalcontact cast that makes use of some components that are alreadyavailable in the marketplace.

It is a further object of the invention to provide an effective totalcontact cast that makes use of some components that are adjustable oradaptable to different size patients.

It is a further object of the invention to provide a method of applyingmaterials and components in order to achieve an effective total contactcast.

These and other objects and advantages of the invention are achieved byproviding a method of constructing a total contact lower leg cast, thatincludes the steps of wrapping a thoroughly cleaned lower leg with foamfrom above the malleoli to mid-calf, covering the foot and lower legwith stockinette, overlapping a predetermined part of thepreviously-applied foam, and covering the foot and ankle with castpadding. A cast tape is applied to the leg over the previously-appliedfoam, and the cast tape is allowed to harden. A foam pad and lateral andmedial malleolar pads are applied to the leg section of the cast with asecond roll of casting tape. A foot and ankle positioning device isapplied to the leg. The foot and ankle positioning device including afoot pad and medial and lateral side extensions extending up the medialand lateral aspects of the ankle and lower leg at a right angle to thefoot pad is applied. A cast tape is applied over the lower leg and footand allowed to harden. A walking support is applied to the foot.

In accordance with another embodiment of the invention, a foot and anklepositioner for a total contact cast is provided that includes a foot bedadapted for application to the bottom of the foot from the toes to theheel. A pair of side extensions is carried by medial and lateral sidesof the foot bed and adapted for extending up the medial and lateralaspects of an ankle and lower leg to which the foot and ankle positioneris applied.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The present invention is best understood when the following detaileddescription of the invention is read with reference to the accompanyingdrawings, in which:

FIG. 1 is a perspective view of the foot and ankle positioning deviceaccording to one embodiment of the invention;

FIG. 2 is a plan view of a foam pad with medial and lateral malleolarextension pads;

FIG. 3 is side elevation illustrating a foot and ankle positioningdevice and a foam pad with medial and lateral malleolar extension padspositioned on the foot and lower leg, with a portion of a stockinettecovering removed to show an underlying padding;

FIG. 4 is a rear elevation view showing foot and ankle positioningdevice and a foam pad with medial and lateral malleolar extension padspositioned on the foot and lower leg;

FIG. 5 is a perspective view of a lower leg and foot after wrapping withan outer bandage; and

FIG. 6 is a perspective view of the completed total contact cast in acast shoe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now specifically FIG. 1 of the drawings, a foot and anklepositioning device 10 is shown. The device 10 includes a foot pad 12preferably formed of a semi-rigid plastic. The foot pad 12 includes aseries of transversely-extending scores 14 that allow the foot pad 12 tobe adjusted as needed for a smaller foot by trimming off excess materialat a selected one of the scores 14. The device 10 also includes a pairof vertically extending side extensions 16 and 18. The side extensions16, 18 may optionally include respective spaced-apart scores 20, 22 thatpermit the side extensions 16, 18 to be shortened by trimming orsnapping off as necessary to accommodate a shorter lower leg.

FIG. 2 illustrates a foam pad 30 that includes a foot bed 32 and lateraland medial malleolar extension pads 34, 36. The foot bed 32 includes aseries of transversely-extending scores 38 that permit the length of thefoam pad 30 to be adjusted as necessary by trimming the excess foammaterial at a selected one of the scores 38. The foam that forms the pad30 is a suitable medical grade open or closed cell foam having apreferred thickness of 2.5 cm.

As is shown in FIG. 3, the foam pad 30 is placed under the foot and themedial and lateral malleolar extension pads 34, 36 are folded upon ontoand covering the medial and lateral aspects of the ankle. This takesplace after preliminary application of protective wrappings and astockinette, as described below. The foot is then placed into the footand ankle positioning device 10. As shown in FIG. 4, the foam pad 30 issufficiently conformable to mold against the various irregularities andasymmetries of the ankle.

The foot and ankle positioning device 10 and foam pad 30 are used inconjunction with the technique explained below. A kit, which includesthe foot and ankle positioning device 10 and foam pad 30 as well asother components, includes by way of illustration:

-   -   1. One roll foam padding such as Comprifoam®: 12 cm×2.5 m×0.4.        cm;    -   2. One 75 cm piece of stockinette;    -   3. 3 rolls of cast padding, which may be a synthetic or cotton        padding;    -   4. 4 rolls of Delta Lite® Conformable cast tape , or two 4″ and        two 3″ rolls of Delta Lite® Conformable cast tape;    -   5. One foot and ankle positioning device 10 and one 2.5 cm thick        foam pad 30 with medial and lateral malleolar extension pads 34,        36; and    -   6. A cast shoe 50, as in FIG. 6, of appropriate size.

The method according to the invention proceeds by first wrapping athoroughly cleaned lower leg and foot with a foam padding 40 such as BSNMedical padding sold under the trademark Comprifoam® from 8 cm above themalleoli to mid-calf. The foot and lower leg is then covered withstockinette 42, overlapping 4 cm. of the Comprifoam® padding 40. SeeFIGS. 3 and 4. The foot and ankle are then covered with cast padding ina manner similar to a standard ambulatory cast.

A conformable cast tape 44, such as BSN Medical cast tape sold under thetrademark Delta-Lite® Conformable is then applied to the leg segmentover the Comprifoam® previously applied, and allowed to harden.

The foam pad 30 is then positioned under the foot with the malleolarpads 34, 36 folded upwardly against the lateral and medial aspects ofthe ankle, attached to the leg section of the cast by application of asecond roll of casting tape and adjusted to the proper size at thescores 38. The foot and ankle positioning device 10 is then applied. Thestructure of the foot and ankle positioning device 10 allows thepractitioner to assure that the foot is held at a right angle to the legwhile finishing the cast without the need of an assistant.

The application of the cast is completed by applying 2-3 rolls ofadditional conformable cast tape 46, which is allowed to harden. Slightweight bearing can be allowed to produce a flat base suitable forambulation. The toe of the cast is left open.

A rocker bottom cast shoe 50 is then applied so that the patient canwalk while wearing the cast.

This cast goes on as easily as a standard walking cast, eliminating fearof application mistakes. Application can be performed by one person,eliminating the need for an assistant. The resulting cast offloads thefoot with a true total contact cast limb-load upper, and provides animproved protective, well-padded foot and ankle. This eliminates thechance of Achilles, malleolar or heel ulcers, or saw cuts on removal.

Alternatively, the foot and ankle positioning device 10 can be appliedto the leg section of the cast after the rolls of cast padding areapplied from toes to the leg and before the second and third layers areapplied in order to maintain the foot and ankle in neutral positionwhile it hardens. The foot and ankle positioning device 10 can alsoincorporate a rocker sole into the design to allow for a removableslipper with a non-skid base that can be worn over the cast similar to arubber overshoe worn to protect shoes from rain. The slipper can thus beremoved for sleeping in order to keep dirt out of the patient's bed.

In this manner, almost all of the patient's weight is removed from theforefoot, where most diabetic sores and wounds occur. Approximately 30percent of the patient's weight is taken on and absorbed by the legportion of the cast. Approximately 55 percent of the patient's weight issupported by the heel. In this regard it is important that the lower legand foot be set and maintained at a right angle, and the structure ofthe foot and ankle positioning device 10 facilitates this orientation bythe right angle between the foot pad 12 and the side extensions 16, 18.

A further 10 percent of the patient's body weight is supported by themidfoot area, leaving only about 5 percent of the patient's weight onthe forefoot. This not only reduces direct downward pressure but alsoreduces shear forces that may occur as the patient pushes off on thefoot during walking.

A total contact cast and total contact cast components according to theinvention have been described with reference to specific embodiments andexamples. Various details of the invention may be changed withoutdeparting from the scope of the invention. Furthermore, the foregoingdescription of the preferred embodiments of the invention and best modefor practicing the invention are provided for the purpose ofillustration only and not for the purpose of limitation, the inventionbeing defined by the claims.

We claim:
 1. A method of constructing a total contact lower leg cast,comprising the steps of: (a) wrapping a thoroughly cleaned lower legwith foam from above the malleoli to mid-calf; (b) covering the foot andlower leg with stockinette that overlaps a predetermined part of thepreviously wrapped foam; (c) covering the foot and ankle with castpadding; (d) applying cast tape to the lower leg over the previouslywrapped foam, and allowing the cast tape to harden; (e) positioning,over the previously applied and hardened cast tape, a foam pad under thefoot and lateral and medial malleolar pads against lateral and medialaspects of the ankle; (f) positioning a foot and ankle positioningdevice on the lower leg, the foot and ankle positioning device includinga foot pad and medial and lateral side extensions extending up themedial and lateral aspects of the ankle and lower leg at a right angleto the foot pad; (g) applying cast tape over the foot and anklepositioning device and the previously applied and hardened cast tape andallowing the cast tape to harden; and (h) applying a walking support tothe foot.
 2. A method according to claim 1, and including the step ofleaving a toe area of the cast open to provide ventilation to the foot.3. A method according to claim 1, and including the step of shorteningthe medial and lateral side extensions to a length medically suitablefor the length of the lower leg.
 4. A method according to claim 1,wherein the walking support comprises a cast shoe.
 5. A method accordingto claim 1, wherein the foot and ankle positioning device is appliedafter the cast tape is applied in step (d) and before the cast tape isapplied in step (g).
 6. A method according to claim 1, and including thestep of shortening the foot pad a length medically suitable for thelength of the foot.
 7. A method according to claim 1, and including thesteps of shortening the medial and lateral side extensions to a lengthmedically suitable for the length of the lower leg and shortening thefoot pad a length medically suitable for the length of the foot.